Rockwell Automation 1395 ControlNet Communication Board - Manual (Page 49)

3–35 Configuration & PLC Interfacing
Publication 1395–5.37– March, 1999
Read Trend Information This function reads the Trend information from the Drive. The Trend
information is broken down into three separate blocks of data. Each
block uses the same function code with the message specifing which
block is to be read.
PLC Block Transfer Instruction Data –
Write Read
Size In Elements: 4 10
Processor Type: PLC-5 PLC-5
Destination Address: N40:0-3 N40:0-9
Message Structure –
Message Header Information:
Word 1: 0
Word 2: 0
Function Code, Word 3: 1549
Write Message Length, Word 4: 8 bytes
0
PLC Message Write PLC Message Read
NOTE: Word 4 of the PLC Message Read instruction is broken down
into two bytes. The High byte contains the status bits
The Low byte contains the Drive message length in bytes.
Header
Word 1
0
Function Code
1549
Message Length
8 bytes
Header
Word 2
Header
Word 3
Header
Word 4
0
Header
Word 1
0
Function Code
1549
See Note
Header
Word 2
Header
Word 3
Header
Word 4
Data
Word 5
Data
Word 6
Parameter
#
Parameter
Data
Parameter
#
Parameter
Data
Data
Word 7
Data
Word 8
Parameter
#
Parameter
Data
Data
Word 9
Data
Word 10
Trend Number – This is an integer number used to specify which
trend buffer the Drive will provide data for.
Trend Buffer #1 – 1
Trend Buffer #2 – 2
Trend Buffer #3 – 3
Trend Buffer #4 – 4